After purchasing a storage card, observant people will find that the capacity of the storage card in the operating system does not match the official nominal capacity, and is less than the nominal capacity. The larger the capacity, the greater the difference.
A storage card with a nominal capacity of 512MB displays only about 490MB in the operating system;
A 1GB storage card only has around 980MB;
And a 4GB storage card is only about 3.7GB.
This is not because manufacturers or distributors deceive consumers by passing off inferior products, but rather due to differences in the calculation methods of storage card manufacturers for capacity and operating systems, as well as differences in unit conversion relationships.
As is well known, binary is used in computers, which results in the calculation of capacity in the operating system being based on a base of every 1024, where every 1024 bytes is 1KB, every 1024KB is 1MB, and every 1024MB is 1GB;
However, memory card manufacturers use a base of 1000 for computing capacity, with 1KB for every 1000 bytes, 1MB for every 1000KB, and 1GB for every 1000MB. The difference in base between the two has resulted in a reduction in memory card capacity.
Taking a 4GB storage card as an example:
Manufacturer's capacity calculation method: 4GB=4000MB=4000000KB=4000000000 bytes
Conversion to operating system calculation method: 4000000000 bytes/1024=3906250KB/1024=3814.697265625MB=3.8GB
At the same time, in the operating system, the storage card is formatted, which also occupies some space on the storage card for system files to use. Therefore, there may be a difference between the displayed storage card capacity and the nominal capacity in the operating system.
The capacity of storage devices such as hard drives that we usually use is calculated in this way, and the larger the capacity, the greater the deviation. For example, a 40GB hard drive only has about 37GB, which is the normal capacity..
